Medical instruments or tools are utilized during surgery for various purposes. In this regard, cutting instruments, such as surgical saws, are utilized to shape and remove bone, for example, for the purpose of preparing a joint for receiving an implant, such as a hip implant. Other types of surgical tools may be used in what are generally termed endoscopic procedures. Endoscopy in the medical field allows internal features of the body of a patient to be viewed without the use of traditional, fully-invasive surgery. Endoscopic imaging systems incorporate an endoscope so as to enable a user to view a surgical site, and endoscopic tools enable non-invasive surgery at the site. Such tools may be shaver-type devices which mechanically cut bone and hard tissue, or radio-frequency (RF) probes which are used to remove tissue via ablation or coagulate tissue to minimize bleeding at the surgical site, to name a few.
In endoscopic surgery, the endoscope is placed in the body at the location at which it is necessary to perform a surgical procedure. Other surgical instruments, such the endoscopic tools mentioned above, are also placed in the body at the surgical site. The surgeon views the surgical site through the endoscope in order to manipulate the tool to perform the desired surgical procedure. Some endoscopes are usable along with a camera head, for the purpose of processing the image data received by the endoscope. The eyepiece of such an endoscope is typically coupled to the camera head, which camera head is connected to a camera control unit.
The development of endoscopes and their companion surgical tools has made it possible to perform minimally invasive surgery that eliminates the need to make a large incision in the patient to gain access to the surgical site. Instead, during endoscopic surgery, small openings, called portals, are formed. One advantage of performing endoscopic surgery is that since the portions of the body that are cut are reduced, the portions of the body that need to heal after the surgery are likewise reduced. Still another advantage of endoscopic surgery is that it exposes less of the interior tissue of the patient's body to the open environment. This minimal opening of the patient's body lessens the extent to which the patient's internal tissue and organs are open to infection.
Surgical instruments, such as surgical saws, shavers, RF devices, camera heads for use in conjunction with endoscopes and other surgical tools, typically incorporate some type of control arrangement located on the instrument which facilitates manual control of the instrument or tool by the surgeon. For example, a conventional RF probe typically includes a control or button arrangement to allow the user to select “CUT” to ablate tissue or “COAG” to coagulate tissue. Similarly, a shaver arrangement typically incorporates a handpiece to which a shaver probe is attached, wherein the handpiece includes a control arrangement with various buttons to control the direction, speed, etc. of the rotating shaver blade. Camera heads usable with endoscopes likewise incorporate control arrangements to allow the user to control various functions of the camera head, such as zoom, pan, white balance, picture, etc.
Due to the type of environment in which the above surgical instruments are utilized, it is necessary to seal internal electrical and mechanical components of the instruments from the external environment, which can have varying humidity levels, or fluids and/or other contaminants present which could harm the instruments and disrupt the functioning thereof. Control arrangements, such as switches, may be mounted in openings formed in the housings of the instruments, and such openings and control arrangements must be adequately sealed from the environment. One known method of sealing control arrangements of this type is to utilize a sealing agent, such as silicone, around the control or switch arrangement at the junction between the arrangement and the instrument housing. Such an arrangement is utilized on the commercially available FORMULA® shaver handpiece used in arthroscopy procedures, as sold by the Assignee hereof. Specifically, the control arrangement includes a keypad including one or more control buttons thereon, which keypad is then held in the housing opening by a cover plate. The cover plate is held in place by screws, and a sealing agent is applied to the juncture between the housing and the cover plate. While this method is effective for its intended purpose, same nonetheless requires additional components and assembly steps during assembly, which can be time-consuming and costly from a manufacturing perspective.
Other known methods include the use of switch components which are permanently press-fit or adhered to the instrument housing. This method, however, accordingly does not allow disassembly of the arrangement, which is sometimes desirable or necessary for maintenance or repair purposes.
In order to obviate or at least minimize the disadvantages of known sealing arrangements, the instant invention includes a control arrangement which cooperates with a housing of the instrument or tool to provide a seal therebetween upon assembly of the control arrangement to the tool housing. The control arrangement includes an actuator member or keypad having a button or buttons thereon associated with a control function of the instrument, a retaining clip configured for securing the control arrangement to the tool housing and a sealing member. The tool housing has a housing wall which defines an opening therein for receiving the control arrangement, and the housing wall includes a sealing surface adjacent the opening. The retaining clip is disposed within a portion of the housing opening defined outwardly of the actuating member, and is resiliently disposed in such opening portion to prevent dislodgement of the control arrangement from the tool housing. Further, the retaining clip, when engaged within the housing opening, causes sealing engagement of the sealing member with the sealing surface of the housing wall automatically upon assembly of the retaining clip to the housing.
This automatic sealing function of the control arrangement when assembled to the tool housing serves to fully seal the arrangement from the exterior environment of the housing, without the need for the application of a sealing agent, such as silicone or the like, to the junction between the control arrangement and the housing.
Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the arrangement and designed parts thereof. The words “forwardly” and “distally” will refer to the direction toward the end of the arrangement which is closest to the patient, and the words “rearwardly” and “proximally” will refer to the direction away from the end of the arrangement which is furthest from the patient. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.